In an automotive environment, there is never an instance where a vehicle does not come across obstacles on the roads. Objects such as other vehicles, pedestrians, objects lying on the road surface, animals, potholes etc., pose as obstacles to a vehicle. The driver of a vehicle needs to maintain extreme care in avoiding collision with such objects to prevent, an accident from, occurring. Nowadays, there are a number of automatic driver assistance systems implemented in the vehicles that provide assistance to the drivers while driving, thereby avoiding accidents on roads and ensuring road safety.
Vehicles nowadays are equipped with Advanced-Driver-Assistance-Systems (ADAS) technology. ADAS provides a safe human-machine interface that alerts the driver to potential problems, or to avoid collisions by implementing safeguards and taking over control of the vehicle. In ADAS, measurement of the distance of objects in the scene from the vehicle is of critical importance, which helps avoid accidents and ensures safe driving.
ADAS and other conventional technologies implement cameras in the vehicle to assist the driver and determine distances to a leading vehicle or another object on the road. Examples of a camera include a stereo camera and single camera, among others. In most systems and methods, the camera determines distances to objects by emitting, a modulated light wave, detecting a corresponding reflected light wave from the object and measuring the shift of the reflected light wave in relation to the emitted light wave. The distance can be calculated because the wavelength and speed of the light are known.
Distance estimation using stereo cameras comes with higher material cost, in addition to an extensive calibration and rectification process. In comparison, single camera based systems are much more prevalent, either through dedicated cameras installed by auto Original Equipment Manufacturer (OEM's), or through standalone dash cameras and smartphone mounted on the dashboard.
It is also important to calculate distance from a vehicle to objects at the front and also at the back. It is further important to calculate distance from a vehicle to objects when lane dimensions are not known. Moreover, a problem with distance estimation can arise when the camera is not mounted orthogonal to the road for the accurate distance measurement.
It is also important to determine the length of a vehicle for multiple use cases such as computing effective braking distance for a vehicle. In case of Vehicle-to-everything (V2X) technology, it, would be useful to localize the position of vehicles in an area. Conventional techniques do not take into consideration measuring the length of the vehicle on which the camera is installed. Also, an efficient method for calculating time to collision is required.
Hence, there is a need for a solution that uses one or more single or monocular cameras to measure the distance to other objects, length of the vehicle where the camera is mounted and a time to collision accurately in real-time, among other things, in a cost effective and accurate manner.